If you really want to stay with AMD, you get a 990FX board and fx-8120 (8150 isn't worth the added price) Select a motherboard that will support the upcoming Piledriver cpus.

If you want a better system on the same price range, you want to go with Intel. Get a Z77 motherboard and a similarly priced Ivybridge cpu. This route is faster than AMD in games and general use and also usually better at multi-threaded applications such as Photoshop. However this platform will not support new CPU architecture. There will be an updated Ivybridge-E line in 2013 but the gains will be
minimal.

So AMD route promises a new CPU line but nothing is guaranteed, you may only see Sandybridge class performance and your Ivybridge setup will still be slightly better than that.

a highly OC 8120 will performe very cloce to a 2500k but the question you need to ask yourself op is do you like to tweek on a computer if you don't go with Intel a intel with a slight oc will out perfome any AMD right now